Abstract: Software maintenance is an important and costly activity of the software development lifecycle. To ensure proper maintenance the software undergoes regression testing. It is very inefficient to re execute every test case in regression testing for small changes. Hence test case prioritization is a technique to schedule the test case in an order that maximizes some objective function. A variety of objective functions are applicable, one such function involves rate of fault detection - a measure of how quickly faults are detected within the testing process. Early fault detection can provide a faster feedback generating a scope for debuggers to carry out their task at an early stage. In this paper we propose a method to prioritize the test cases for testing component dependency in a Component Based Software Development (CBSD) environment using Greedy Approach. An Object Interaction Graph (OIG) is being generated from the UML sequence diagrams for interdependent components. The OIG is traversed to calculate the total number of inter component object interactions and intra component object interactions. Depending upon the number of interactions the objective function is calculated and the test cases are ordered accordingly. This technique is applied to components developed in Java for a software system and found to be very effective in early fault detection as compared to non-prioritize approach.